My 405 is a write-off after a minor collision which has damaged the NSF. The engine is strong, starts fine, uses almost no oil and does 45 mpg. I wondered if there is any point even considering a complete swap of the engine and gearbox into another 405? I've seen one with a blown engine.

A lot depends on what you will be paying for labour, and if you can be certain that the other one doesn't need other work (rear suspension, etc.) Don't know the official time for an engine out/in on a 405, but I wouldn't have thought you were looking at more than 5-6 hours

If you've only had minor damage to the NSF, it may be a cheaper option to have yours repaired. I'm sure you can get parts from a scrappie. Might be easier to get the car with the blown engine and swap the damaged parts over rather than swop engines.

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These are the views of Robin the Technician with 35 years in the trade. I fix, therefore I am...